Ink jet type recording head

ABSTRACT

An ink jet type recording head having plural pressure generating units which are arranged on a passage unit in a plurality of arrays in a recording head moving direction, and in which reservoirs are formed so as to cross over the pressure generating units per each of the plurality of arrays.

This application is a continuation in part of application Ser. No.08/901,787, filed Jul. 28, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ink jet type recording head in whicha piezoelectric vibrator or other pressure generating means is providedin a region of a pressure generating chamber communicating with a nozzleopening. Ink drops are generated when the pressure generating chamber iscompressed by the deflection vibration of the piezoelectric vibrator.

2. Description of the Related Art

In order to conduct printing at high speed and high density, it would bedesirable to increase the number of nozzle openings per recording head.Since an ink jet type recording head requires as many pressure applyingmeans for applying pressure to ink as the number of nozzle openings andrequires uniform pressure applying performance, the pressure applyingmeans may be in the lowest production yield among head forming members.

In order to overcome this problem, the following recording head formingtechnique has been adopted. A pressure generating unit of a recordinghead is designed to have a comparatively small number of pressuregenerating means, and a plurality of such pressure generating units arearranged in a main scanning direction on a relatively easilymanufacturable passage unit that has nozzle openings, reservoirs, andthe like. Accordingly, the recording head can be formed with a largenumber of nozzle openings.

However, in this design, the thickness of the walls of adjacent pressuregenerating units is larger than a nozzle opening arraying pitch.Therefore, the pressure generating units must be arranged so as to beshifted by the width of a single unit, which in turn imposes the problemthat the width of the recording head becomes about twice as much as thewidth of the pressure generating unit. In addition, only a smallinclination produced at the time of attaching the recording head to therecording apparatus lead to a grave error in the dot forming positionbetween nozzle openings for black ink and nozzle openings for colorinks, and this grave error greatly affects print quality. Therefore,highly accurate positioning is required for pressure generating unitassembling operation, which in turn makes the assembling operationdifficult.

SUMMARY OF THE INVENTION

The ink jet recording head of the present invention has a plurality ofpressure generating units (sometimes called actuator units), eachincluding a plurality of pressure generating chambers and means forgenerating a pressure inside the pressure generating chambers, and apassage unit on which the pressure generating units are arranged, thepassage unit having reservoirs formed therein that extend continuouslyfrom one pressure generating unit to an adjacent pressure generatingunit.

The pressure generating units can have different constructions, and bearranged in different ways, examples of which are described below.However, the construction of the pressure generating units and the wayin which the pressure generating units are arranged are not intended tolimit the invention.

For example, the pressure generating units might be arranged end to endon the above passage unit by adjusting the pitch between pressuregenerating chambers relative to a nozzle opening pitch, and adjustingthe width of partition walls on outermost ends of each pressuregenerating unit relative to the width of a partition wall separatingadjacent pressure generating chambers and the nozzle opening pitch, asdescribed in co-pending U.S. patent application Ser. No. 08/681,376,entitled “LAMINATED INK JET RECORDING HEAD WITH PLURAL ACTUATOR UNITSCONNECTED AT OUTERMOST ENDS”, filed Jul. 23, 1996, which application isincorporated herein by reference.

As another example, the pressure generating units might be arranged onthe above passage unit in the manner described below.

Specifically, the pressure generating chambers are inclined at an angleθ with respect to the arrangement direction; outer walls of the pressuregenerating units in the arrangement direction are inclined at an angle θwith respect to the arrangement direction, thereby providing aninclination for each the pressure generating units; the pressuregenerating units are arranged on the passage unit such that each thepressure generating unit is shifted in a sheet forward direction alongthe inclination of an adjacent one of the pressure generating units awayfrom a position aligned with the adjacent pressure generating unit; andan amount of shift between each the pressure generating unit and theadjacent pressure generating unit is set such that a pitch (hereinafterreferred to as the “design pitch” whenever applicable) between firstopposing ones of the pressure generating chambers that oppose each otheracross the outer walls of the pressure generating unit and the adjacentpressure generating unit is equal to a pitch between second opposingones of the pressure generating chambers that oppose each other on thepressure generating unit.

Since the outer walls of the opposing pressure generating units areinclined with respect to a line orthogonal to a pressure generatingchamber arraying direction, a nozzle opening arraying pitch at aboundary region between the opposing pressure generating units can beadjusted to the design pitch by shifting one of the opposing pressuregenerating units in parallel along the outer walls thereof. That is, ifone of the opposing pressure generating units is shifted in parallelalong the outer walls thereof, the distance between the pressuregenerating chambers belonging to the opposing pressure generating unitsin the pressure generating chamber arraying direction is changed, sothat the nozzle opening arraying pitch at the boundary region betweenthe opposing pressure generating units can be adjusted to the designpitch. Since this shifted distance is extremely small compared with thewidth of each pressure generating unit, the width of the recording headas a whole can be made smaller than a product of the width of apressure-generating unit and the number of pressure generating unitsarranged in the recording head moving direction.

Therefore, a first object of the invention is to provide an ink jet typerecording head capable of increasing the number of nozzle openings perrecording head using a plurality of units without significantlyincreasing the width of the recording head.

Further, a second object of the invention is to provide an ink jet typerecording head capable of jetting a plurality of kinds of ink drops byproviding a plurality of reservoirs, each reservoir communicating with aplurality of pressure generating units.

Still further, a third object of the invention is to provide a flexiblecable capable of being connected to a plurality of actuators with ease.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a recording head, which is anembodiment of the invention;

FIG. 2 is a diagram showing an ink passage structure centering onpressure generating chambers with a vibrating plate and ink supply tubesremoved;

FIG. 3 is a diagram showing an ink jet type recording head, which is anembodiment of the invention in the form of a sectional structure closeto pressure generating chambers;

FIG. 4 is a front view showing an embodiment of an ink passage formingboard;

FIG. 5 is a diagram showing a layout of pressure generating chambers ina pressure generating unit;

FIG. 6 is a diagram showing a positional relationship between twopressure generating units forming a single array;

FIG. 7 is a diagram showing an embodiment of a flexible cable thatsupplies drive signals to a plurality of pressure generating units ineach pressure generating unit array of the recording head;

FIG. 8 is a diagram showing an arrangement of segment electrodes,connecting patterns, and connecting terminal portions of the recordinghead;

FIG. 9 is a sectional view showing a condition in which the flexiblecable has been connected;

FIG. 10 is a diagram showing another embodiment of the invention in theform of a reservoir structure;

FIG. 11 is a diagram showing an embodiment of a passage unit used in theaforementioned recording head as viewed from a relationship between anozzle opening arrangement and pressure generating units; and

FIG. 12 is a diagram showing another embodiment of the invention in theform of a relationship between pressure generating units and reservoirs.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 and FIG. 2 show an embodiment of the invention. Referencenumerals 1 and 2 denote pressure generating units that will be describedlater. The pressure generating units are designed under the samespecification. A plurality of pressure generating units are arranged inthree arrays, each array including two vertically arranged units. Thesethree arrays of pressure generating units are fixed to a surface of apassage unit 6, which will be described later, so as to be shifted at adistance ΔL, which will be described later, in a main scanningdirection, i.e., in a recording head moving direction equidistantly. Thepassage unit 6 functions also as a fixing member.

Each of the pressure generating unit 1 and the pressure generating unit2 includes two independent arrays of pressure generating chambers 4, 5.The pressure generating chambers 4, 4 of the upper and lower pressuregenerating units 1, 2, and the pressure generating chambers 5, 5 of theupper and lower pressure generating units 1, 2 are arranged torespectively communicate with reservoirs 8, 9 that are formed in thepassage unit 6. Each reservoir extends so as to cross over the twopressure generating units 1, 2.

Ink introducing ports 11, 12 are formed at diagonal points of theconfronting upper and lower pressure generating units 1, 2 for each ofthe three pressure generating unit arrays A, B, C. The ink introducingports 11, 12 supply ink to the reservoirs 8, 9, respectively. Ink supplytubes 14, 15 are erected on the passage unit 6 so as to communicate wishthe ink introducing ports 11, 12. Accordingly, ink can be suppliedindependently to the reservoirs 8, 9 that communicate with the pressuregenerating chambers 4, 5 belonging to the same pressure generating unitarray.

Since the reservoirs 8, 9 are independent of each other, ink drops ofdifferent colors can be jetted out of the respective nozzle openingarrays A-1, A-2, B-1, B-2, C-1, C-2. For example, black ink is suppliedto the reservoirs corresponding to nozzle opening arrays A-1, A-2, B-1by arranging the nozzle opening arrays A-1, A-2, B-1 at the same pitchand so as to be close to one another; and cyan, magenta, and yellow inksare supplied to the reservoirs corresponding to the nozzle openingarrays B-2, C-1, C-2 by arranging the nozzle opening arrays B-2, C-1,C-2 so as to coincide with an auxiliary scanning direction, i.e., with aline parallel to a carriage moving direction. Accordingly, a recordinghead that can produce high-density monochromatic and color images can beobtained.

Further, the ink introducing ports 11, 12 that supply inks from externaltanks to the reservoirs 8, 9 of the respective pressure generating units1, 2 are arranged at the diagonal points of the two pressure generatingunits 1, 2 belonging to each of the respective arrays A. B, C in thisembodiment. Therefore, the ink supply tubes 14, 15 can be arranged whileeffectively utilizing the dead space of the stepped portions formed bythe boundaries of the respective arrays A, B, C. As a result, therecording head can be downsized as a whole.

FIG. 3 shows embodiments of the aforementioned pressure generating unitand the passage unit 6. Since each of the pair of pressure generatingunits 1, 2 has the same construction, only the pressure generating unit1 will be described.

The pressure generating unit 1 will be described first. Referencenumeral 21 denotes a spacer. The spacer 21 has the pressure generatingchambers 4, 5 arranged in a plate made of a ceramic plate such as azirconia (ZrO₂) plate having a thickness suitable for forming thepressure generating chambers 4, 5 whose depth is about 150 μm. As shownin FIG. 5, the pressure generating chambers 4, 5 are arranged so thatthe axial line along the length of each of the pressure generatingchambers 4, 5 forms an acute angle θ with respect to nozzle opening 38,39 arraying lines D, E. The acute angle θ is preferably set to begreater than 45 degrees and less than 90 degrees (i.e. 45°<θ<90°)

Further, outer walls 1 a, 1 b extending along the pressure generatingchamber 4, 5 arraying direction (vertical direction as viewed in FIG. 5)are formed so as to be substantially parallel to the axial lines alongthe length of the pressure generating chambers 4, 5. Outer walls 1 c, 1d in the other direction (horizontal direction as viewed in FIG. 5) areformed so as to be substantially parallel to the nozzle opening 38, 39arraying lines D, E. The outer walls 1 a, 1 b adjacent to the otherpressure generating unit are formed so that the thicknesses thereof W1,W2 are as thin as possible.

By arranging the pressure generating chambers 4, 5 so that the axialline thereof is inclined by the acute angle θ with respect to the nozzleopening arraying line, pressure generating chambers whose length islarger can be arranged within pressure generating units of the samewidth compared with a pressure generating chamber 4′ that is arranged ata right angle. Therefore, this pressure generating chamber arrangementcould allow a designer to meet capacity requirements with more ease inthe case where the width of a pressure generating unit must be reducedfor high-density design.

Reference numeral 22 denotes a vibrating plate. The vibrating plate 22is made of a material that provides a sufficient bonding force whenfired integrally with the spacer 21 and also is elastically deformableby deflection displacement of piezoelectric vibrators 23, 24 that willbe described later. The vibrating plate 22 is made of the same zirconiathin plate as the spacer 21 in this embodiment, the thickness of thevibrating plate being 10 μm.

Reference numerals 23, 24 denote the aforementioned piezoelectricvibrators. The piezoelectric vibrators 23, 24 are formed on commonelectrodes 25, 26 by sintering a green sheet made of a piezoelectricmaterial, the common electrodes 25, 26 being formed on the vibratingplate 22. Segment electrodes 27, 28 are formed on the piezoelectricvibrators 23, 24.

The passage unit 6 will be described next. A cover plate 30 that sealsthe other surface of the spacer 21 in FIG. 3, is made of a zirconia thinplate whose thickness is 150 μm in this embodiment. Formed in the coverplate 30 are communicating holes 31, 32 and ink supply ports 33, 34. Thecommunicating holes 31, 32 connect the nozzle openings 38, 39 of anozzle plate 3 to the pressure generating chambers 4, 5. The ink supplyports 33, 34 allow ink in the reservoirs 8, 9 to flow into the pressuregenerating chambers 4, 5 while connecting the reservoirs 8, 9 to thepressure generating chambers 4, 5 and ensuring a passage resistancenecessary for jetting ink drops.

An ink supply passage forming board 35 is formed of a plate memberhaving corrosion resistance such as a stainless steel whose thickness issuitable for forming ink passages, e.g., 150 μm. Formed in the inksupply passage forming board 35 are through holes serving as thereservoirs 8, 9 and communicating holes 36, 37 connecting the pressuregenerating chambers 4, 5 to the nozzle openings 38, 39. These reservoirs8, 9 are divided into upper regions 8 a, 9 a and lower regions 8 b, 9 bso as to match the positions of the pressure generating chambers 4, 5 ofthe respective pressure generating units 1, 2 that are fixed so as to beshifted by ΔL on the cover plate 30 as shown in FIG. 4. Each of thereservoirs 8, 9 is formed as a single continuous hole with the upperregion 8 a, 9 a thereof shifted by ΔL with respect to the lower region 8b, 9 b thereof. The ink introducing port 11 is formed in the lower endof the reservoir 8, and the ink introducing port 12 is formed in theupper end of the reservoir 9, the ink introducing ports 11, 12 allowingink from an external source to flow thereinto.

The nozzle plate 3 has two sets of nozzle openings 38, 39 that confronteach other at a predetermined distance L. The set of nozzle openings 38in the pressure generating unit 1 is arranged so as to be shifted by ΔLwith respect to the set of nozzle openings 38 in the pressure generatingunit 2 in the main scanning direction. This shifting distance ΔL isselected in such a manner that the respective pressure generating units1, 2 do not overlap one upon another when the two pressure generatingunits 1, 2 are fixed and in such a manner that a nozzle opening pitch inthe sheet forward direction between the confronting pressure generatingunits 1, 2 equals a pitch P0 between a nozzle opening 38 and a nozzleopening 39 designed for a single pressure generating unit.

That is, the first pressure generating unit 1 and the second pressuregenerating unit 2 that form each of the arrays A, B, C are fixed to thepassage unit 6 so as to be shifted by ΔL in such a manner that thedistance P1 between the lowermost nozzle opening 39 of the firstpressure generating unit 1 and the uppermost nozzle opening 38 of thesecond pressure generating unit 2 in the boundary region between thefirst pressure generating unit 1 and the second pressure generating unit2 coincides with the nozzle opening design pitch P0, and so as toprovide a gap ΔG if necessary. That is, since the lower outer wall 1 band the upper outer wall 2 a of the vertically arranged first and secondpressure generating units 1, 2 are arranged so as to be inclined at theangle θ with respect to the nozzle opening arraying lines D, E, thepitch P1 at the boundary region between the first and second pressuregenerating units 1, 2 can be arranged to coincide with the design pitchP0 set for a pressure generating unit only by setting an extremely smallshifting distance ΔL compared with the width of each of the pressuregenerating units 1, 2.

The thus constructed recording head can print data similarly to theconventional recording head by applying a print signal while shiftingthe print timing by a number of dots corresponding to the distance ΔLbetween the first pressure generating unit 1 and the second pressuregenerating unit 2 belong to each pressure generating unit array.Further, between the pressure generating unit arrays, dots belonging toeach array can be printed so as to be superposed one upon another byapplying a print signal while shifting the print timing by a number ofdots corresponding to the distance between the arrays A, B, C.

While the case where there are three pressure generating unit arrays hasbeen described in the aforementioned embodiment, it is apparent that theinvention can be similarly applied to a case where there are four ormore arrays.

FIG. 7 shows an embodiment of a flexible cable suitable for supplyingdrive signals to the aforementioned recording head. The flexible cable55 is prepared using a flexible conductive material that is formed bybonding a metal foil made of copper or the like to a heat-resistantelectrically insulating base member such as polyimide. The flexiblecable 55 is formed by cutting such flexible conductive material in thefollowing manner. The length of the flexible cable 55 is such that thepressure generating units 1, 2 forming the recording head can be coveredthereby. The width of the flexible cable 55 is large enough to allow thewidthwise ends thereof to come in contact with connecting terminalportions 42, 42, 42, . . . , 43, 43, 43 . . . that are connected to thesegment electrodes 27, 27, 27, . . . , 28, 28, 28, . . . and toconductive patterns 40, 40, 40, . . . , 41, 41, 41 . . . , respectively.More preferably, the flexible cable 55 is formed by cutting the flexibleconductive material into bandlike pieces, each piece having a widthlarger by about ΔW, so that the bandlike, pieces can be connected bybending while having a predetermined space with respect to the segmentelectrodes 27, 28 of the piezoelectric vibrators 23, 24 as shown in FIG.9. In the thus formed flexible cable 55, tabs 53, 53, 53, . . . , 54,54, 54, . . . are formed on the end portions of side surfaces or edges51, 52 that extend along the length of the flexible cable 55 so as toextend in a vertical direction with respect to the side surfaces 51, 52.The tabs have the same arraying pitch as the connecting terminalportions 42, 42, 42, . . . , 43, 43, 43, . . . of the pressuregenerating unit 1. These tabs 53, 53, 53, . . . , 54, 54, 54, . . . areformed Z-shaped while bent along the lines parallel to the side surfaces51, 52.

This embodiment is designed in such a manner that semiconductorintegrated devices 56, 57 that produce drive signals based on a printsignal applied from outside are mounted on the flexible cable 55, andthat the drive signals outputted from the semiconductor integratedcircuits 56, 57 are supplied to the tabs 53, 53, 53, . . . , 54, 54, 54,. . . formed integrally with conductive patterns 58, 59. A print signalfrom an external drive circuit is applied to these semiconductorintegrated devices 56, 57 by a conductive pattern 60 or 61 that extendstoward one side of the flexible cable 55.

In the thus constructed flexible cable 55, the side surfaces 51, 52thereof extend in parallel to the side walls of the vertically arrangedpressure generating units 1, 2, and the tabs 53, 53, 53, . . . , 54, 54,54, . . . are positioned so as to confront the connecting terminalportions 42, 42, 42, . . . , 43, 43, 43, . . . of the respectivepressure generating units 1, 2. The flexible cable 55 is bonded with theconducting relationship formed by soldering or the like. In positioningthe flexible cable 55, the tabs 53, 53, 53, . . . , 54, 54, 54, . . .are formed so as to be substantially vertical with respect to the sidesurfaces 51, 52 of the flexible cable 55. Therefore, when the sidesurfaces 51, 52 of the flexible cable 55 are positioned so as to extendin parallel to the left and right side walls of the pressure generatingunits 1, 2 and so as to correspond to the respective connecting terminalportions 42, 42, 42, . . . , 43, 43, 43, . . . as viewed in FIG. 8, allthe tabs 53, 53, 53, . . . , 54, 54, 54, . . . can be arranged atconnectable positions.

FIG. 10 shows a second embodiment of the invention. Reference numerals1, 1, 1, 1 denote the aforementioned pressure generating units. Thesepressure generating units are fixed to a passage unit 70, which will bedescribed later, in such a manner that the pressure generating units areshifted by the predetermined distance ΔL from each other so that thenozzle openings are pitched uniformly at the boundary regiontherebetween as described above. As shown in FIG. 11, the passage unit70 communicates with the pressure generating chambers 4, 5 of thepressure generating units 1, 1, 1, 1, and has nozzle openings 71, 71,71, . . . , 72, 72, 72, . . . formed at a predetermined pitch in such amanner that two horizontally adjacent nozzle openings are on a singleline.

Further, a slenderly extending reservoir 73 is formed in one side (onthe left side as viewed in FIG. 10) so as to communicate with all thepressure generating chambers 4 of the four pressure generating units 1,1, 1, 1. On the other hand, reservoirs 74, 75, 76 are formed on theother side (on the right side as viewed in FIG. 10), each reservoirbeing formed so as to communicate with a number of pressure generatingchambers 5 of the four pressure generating units 1, 1, 1, 1, the numberbeing defined by dividing all the pressure generating chambers 5 intothree equal parts. That is, each of the reservoirs 74, 75, 76 covers atotal of 16 pressure generating chambers in this embodiment. The blackink is supplied to the reservoir 73 through an ink introducing port 77,and the yellow, magenta, and cyan inks are supplied to the reservoirs74, 75, 76 through ink introducing ports 78, 79, 80.

The thus constructed recording head is mounted on the carriage in such amanner that the lines of arrangement of the respective nozzle openings71, 71, 71, . . . , 72, 72, 72, . . . coincide with the auxiliaryscanning direction, i.e., the sheet forward direction. As a result, theblack ink is supplied to the reservoir 73 formed on one side of thepassage unit 70, and the yellow, magenta, and cyan inks are supplied tothe three reservoirs 74, 75, 76 formed on the other side of the passageunit 70. A dot forming signal for black is applied to all thepiezoelectric vibrators 23 of the pressure generating chambers 4 on onesides of the respective pressure generating units 1, 1, 1, 1; a dotforming signal for yellow is applied to all the piezoelectric vibrators24 corresponding to the pressure generating chambers 5 communicatingwith the reservoir 74; a dot forming signal for magenta is applied toall the piezoelectric vibrators 24 corresponding to the pressuregenerating chambers 5 communicating with the reservoir 75; and a dotforming signal for cyan is applied to all the piezoelectric vibrators 24corresponding to the pressure generating chambers 5 communicating withthe reservoir 76.

Therefore, when a dot forming signal for black has been fed, thepiezoelectric vibrators 23 apply pressure to the pressure generatingchambers 4, 4, 4, . . . , so that ink drops are jetted out of the nozzleopenings 71, 71, 71, . . . on one side. Further, when dot formingsignals for color inks have been fed, the piezoelectric vibrators 24,24, 24 apply pressure to the pressure generating chambers 5, 5, 5, . . .of the other side of the pressure generating units 1, 1, 1, 1, so thatdots of color inks can be formed along the same line as the dots formedby the black ink.

By the way, since the nozzle openings 72, 72, 72 . . . are pitched at aninterval substantially equal to thirteen (13) dots in the sheet forwarddirection, dots of different colors can be formed at the same positionby causing the sheet forward distance to coincide with the recordingwidths of the respective colors. The printing operation is performed byrepeating such process.

On the other hand, in the case where text data and monochromatic imagedata are to be printed, if a drive signal is applied only to thepiezoelectric vibrators 23 corresponding to the vertically arrangedpressure generating chambers 4 on one side, data can be printed in arecording sheet region that is approximately 3 times larger in the sheetforward direction than in the case of color printing.

While the example in which a recording head is formed of four pressuregenerating units has been described in this embodiment, it is apparentthat similar advantages can be provided by an example in which there areso many pressure generating chambers and by an example in which two ormore actuators are used, as long as such a structure that the pressuregenerating chambers and the actuators are divided into a region forblack on one side and a plurality of regions on the other side so as toallow inks to be supplied independently to the respective regions.

FIG. 12 shows another embodiment of the invention. Reference numerals 1,1, 1 denote three pressure generating units that apply pressure to ink,the pressure-generating units 1, 1, 1 having the same structure. It isdesired that the three pressure generating units be arranged on apassage unit 80 so as to be shifted at a predetermined distance in thesheet forward direction so that one side of an array of the pressuregenerating chambers out of the two arrays of pressure generatingchambers belonging to one pressure generating unit is aligned with oneside of one array of the pressure generating chambers belonging to theother adjacent pressure generating unit in the sheet forward direction.

Nozzle openings are formed in the passage unit 80. The nozzle openingscommunicate with the pressure generating chambers of each pressuregenerating unit 1. It is desired that the nozzle openings be formed sothat one array of the pressure generating chambers out of the two arraysof the pressure generating chambers belonging to one pressure generatingunit is aligned with the other array of the pressure generating chambersbelonging to the other adjacent pressure generating unit in the sheetforward direction. Further, ink introducing ports 81, 82, 83, 84, 85, 86are arranged so as to be positioned on both sides of the respectivepressure generating units 1, 1, 1, and reservoirs 87, 88, 89, 90, 91, 92that independently communicate with the pressure generating chambers 4,4, 4, . . . , 5, 5, 5, . . . of the respective pressure generating units1, 1, 1 are formed.

According to this embodiment, a recording apparatus capable of making acolor printing using six colors can be downsized in the main scanningdirection. That is, the recording apparatus capable of making a colorprinting using six colors by supplying inks of different colors, i.e.,black, yellow, dark magenta, light magenta, dark cyan, and light cyaninks from external sources to the respective ink introducing ports 81 to86 can be implemented so as to be downsized in the main scanningdirection.

While the case where three pressure generating units are used has beendescribed in this embodiment, a recording head that can jet ink drops ofsix or more different colors can be implemented by increasing the numberof pressure generating units arranged in the sheet forward direction.

Further, while the case where the recording head uses a plurality ofunits that expands and contracts the pressure generating chambers bydeflection vibration of the piezoelectric vibrators in theaforementioned embodiments, similar advantages can be provided byapplying the invention to an example in which one end of a piezoelectricvibrator of a vertical vibration mode is caused to come in contact withan elastic plate or to an example in which pressure is applied to apressure generating chamber by heating the pressure generating chamberusing a heating element.

Further, while the case where an actuator in which the pressuregenerating chambers are inclined with respect to the nozzle openingarraying lines has been described in the aforementioned embodiments, itis apparent that the invention can be applied to a structure in which anozzle opening arraying pitch in a region where adjacent pressuregenerating units confront each other can be made equal to a nozzleopening arraying pitch designed for a pressure generating unit.

What is claimed is:
 1. An ink jet type recording head comprising: aplurality of pressure generating units, each pressure generating unitcomprising: a plurality of pressure generating chambers, and means forgenerating a pressure inside said pressure generating chambers; and apassage unit on which said pressure generating units are arranged, saidpassage unit having reservoirs formed therein, said reservoirs extendingcontinuously from one pressure generating unit to an adjacent pressuregenerating unit.
 2. An ink jet type recording head according to claim 1,wherein the pressure generating units are fixed to the passage unit in aplurality of arrays in a recording head moving direction.
 3. An ink jettype recording head according to claim 1, wherein the passage unit hasan array of nozzle openings independently connected to each array ofpressure generating chambers juxtaposed in the recording head movingdirection.
 4. An ink jet type recording head according to claim 1,wherein ones of the pressure generating chambers in one array areconnected to a common reservoir, and ones of the pressure generatingchambers in another array are divided into a plurality of regions in asheet forward direction so that the pressure generating chambersbelonging to each of the plurality of regions are connected to adifferent reservoir, respective reservoirs being supplied with inksindependently of one another.
 5. An ink jet type recording headaccording to claim 4, wherein a black ink is supplied to the commonreservoir, and color inks are supplied to the reservoirs connected tothe pressure generating chambers being divided into the plurality ofregions.
 6. An ink jet type recording head according to claim 1, whereinthe passage unit has two arrays of nozzle openings that are arranged soas to be aligned with each other in the sheet forward direction.
 7. Anink jet type recording head according to claim 1, further comprising aflexible cable, the flexible cable having side edges thereof extendingin parallel to side walls of each of the plurality of pressuregenerating units and having connecting portions thereof formed close tothe side edges in such a manner that the connecting portions extendvertically along the side edges, the connecting portions being connectedto connecting terminal portions of each pressure generating unit.
 8. Anink jet type recording head according to claim 7, wherein the connectingportions of the flexible cable are tabs.
 9. An ink jet type recordinghead according to claim 8, wherein each tab is bent so as to beZ-shaped, and a space is provided between a portion of the flexiblecable and the pressure generating means.
 10. An ink jet type recordinghead according to claim 1, wherein the pressure generating meanscomprises a piezoelectric vibrator.